Field of the Invention
The present invention relates to a distributed feeding device that feeds power to vehicles such as railway models and a control system, and especially relates to divided feed using pulse width modulation (PWM).
Description of the Related Art
Conventionally, in layouts in which a model vehicle such as a railway model travels, control systems that cause a plurality of vehicles to travel while individually controlling the plurality of vehicles are known. As one of such control systems, a system called digital command control (DCC) is widely spread in Europe and the United States, and is also spreading in Japan. In the DCC, a decoder is mounted in a vehicle to be controlled, and a command from a controller is transmitted to the decoder at the vehicle side through a rail that configures the layout. In this command, an address is attached, and only the decoder corresponding to the specified address executes the command, so that drive of a travel motor, lighting of lights, and the like are individually controlled. An alternating current of about 12 V flows in the layout on a steady basis, and the decoder converts the alternating current into a direct current according to the command and drives a motor mounted on the vehicle, so that a vehicle speed is controlled. Although the DCC has a high degree of freedom as a control system, the decoder itself is very expensive and in addition, time-consuming machining often needs to be applied to the vehicle to mount the decoder. Further, some knowledge is required. Therefore, a barrier to introduction is high for users. Further, since the power feed to the plurality of vehicles that travel on the layout is controlled by the one feeding system, a rated current is higher than conventional direct current control (DC control), and there is concern over safety, such as electric shock or short circuit when carelessly touching the rail. From these problems, the DCC has not yet been superior to the conventional direct current control.
Even the conventionally widely spread direct current control can allow the plurality of vehicles to travel at the same time by devising the feeding system of the layout, and switching the power feed to the layout in real time according to the travel of the vehicles. For example, JP 2003-225472 A discloses a vehicle driving device that individually controls a plurality of vehicles by dividing a railway model layout into a plurality of electrically separated sections, and causing a current to flow only to a necessary section, that is, performing divided feed on a section basis. Further, this vehicle driving device prevents collision of vehicles before anything happens by performing exclusive control of not allowing a plurality of vehicles to enter a section as a destination, in addition to simple divided feeding.
Further, JP 2010-252955 A discloses a railway model automatic driving device that performs divided feed on a section basis using pulse width modulation. To be specific, a plurality of motor drivers allocated to respective sections is built in a microcomputer unit configured from a one-chip microcomputer, and pulsed drive voltages output from the respective motor drivers are supplied to a power vehicle on a rail on a section basis. One motor driver is independently configured for each section by using one channel of a 16-bit timer mounted on the one-chip microcomputer as speed control PWM waveform generating unit. Further, JP 2010-252955 A points out that, although not disclosing a specific configuration, it is necessary to adjust phases between channels because power feed from motor drives from two places is added when the power vehicle (motor-mounted vehicle) is on a boundary of sections.
As pointed out in JP 2010-252955 A, in the section-divided feed using pulse width modulation, when a vehicle traveling on the layout enters from the current section to the next section, that is, in the process where the vehicle travels across the adjacent sections, a phenomenon of rapid acceleration of the vehicle may occur against an instruction of the controller. Further, like the one-chip microcomputer (microcomputer unit) of JP 2010-252955 A, when the power feed is collectively performed from a single feed source to the sections, it is necessary to pull out a large number of wires of the feeding system from one place to all of sections including a section close to the feed source and a section distant from the feed source. Therefore, in the entire layout, a wire amount of the feeding system becomes very large. This increase in the wire amount imposes a heavy burden on a user who creates the layout. Further, a large current, which is sufficient to drive the motor mounted on the vehicle, flows in the feeding system, and a high-frequency component is included because the drive current has a pulse waveform in the case of pulse width modulation. Therefore, the wires may become a noise source that negatively affects peripheral devices. Therefore, from the perspective of suppression of unnecessary radiation, the increase in the wire amount of the feeding system is not favorable.